deleteman

let array1 = [1,2,3,4]

//Copying an array
let copyArray = [...array1]
copyArray.push(4)
console.log(array1)
console.log(copyArray)
/*
[ 1, 2, 3, 4 ]

deleteman

for(let a = 0, b = 0; a < 10 && b < 100; a++, b+=10) {
   console.log(a, b)
}
/*
0 0
1 10
2 20
3 30
4 40
5 50

deleteman

for(let a = 0, b = 0; a < 10 && b < 100; console.log("Your counters are at:", ++a, b+=2)){}
/*
Your counters are at: 1 2
Your counters are at: 2 4
Your counters are at: 3 6
Your counters are at: 4 8
Your counters are at: 5 10
Your counters are at: 6 12
Your counters are at: 7 14
Your counters are at: 8 16

deleteman

function isItDone(a) {
 console.log("fn called!")
 return a < 10
}

for(let a = 0; isItDone(a); a++) {
 console.log(a)
}
/*
fn called!

deleteman

let myMap {
  uno: 1,
  dos: 2,
  tres: 3
}
for(let key in myMap) {
  console.log(key, "=", myMap[key]);
}
/*
uno = 1

deleteman

for(let k in "Hello World!") {
   console.log(k)
}
/*
0
1
2
3
4
5

deleteman

for(let char of "Hello World!") {
  console.log(char)
}
/*
H
e
l
l
o
 

deleteman

const fs = require("fs")

async function read(fname) {
    return new Promise( (resolve, reject) => {
        fs.readFile(fname, (err, content) => {
            if(err) return reject(err)
            resolve(content.toString())
        })
    })
}

deleteman

let myArr = ["hello", "world"]
for([idx, value] of myArr.entries()) {
    console.log(idx, '=', value)
}
/*
0 '=' 'hello'
1 '=' 'world'
*/

deleteman

const fs = require("fs")

async function read(fname) {
    return new Promise( (resolve, reject) => {
        fs.readFile(fname, (err, content) => {
            if(err) return reject(err)
            resolve(content.toString())
        })
    })
}